Jon,

While I agree that fuel will seek its own level, I also believe that the high speed pumps shoot the fuel in faster than the inter connects and venting systems can handle, hence the spitting. I do not know how the 45's are plumbed, but on mine, the main tank is filled from the nozzle. Other 40's have the aux tank being filled first. I have never been spit on even at max pump speed, perhaps it is the single fill, perhaps it is because the main is taking the fuel...dunno. My best guess is that once my main fills, although the aux is filling as well but at a slower rate, I get the auto shut off and the overflow is absorbed by the aux tank...no spitting mainly because I have extra room for additional fuel. My gauge reads full and I think that my tank (s) are at capacity when in reality I may have a long way to go.